Optic system for light guide with controlled output

• US 8,641,257 B2
• Filed: 12/31/2009
• Issued: 02/04/2014
• Est. Priority Date: 01/02/2009
• Status: Active Grant

• Current Assignee: Rambus Delaware
• Original Assignee: Rambus Delaware LLC (Rambus Inc.)
• Inventors: Richardson, Brian E.
• Primary Examiner(s): Ton, Anabel
• Application Number:
  US13/143,341
• Publication Number:
  US 20110267838A1
• Time in Patent Office: 1,496 Days
• Field of Search: 362/97.1, 362/296.01, 362/607, 362/616, 362/615
• US Class Current: 362/615
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/3522 the optical element enabling or impairing total internal reflection using evanescent coupling G02B6/3536
• CPC Class Codes: G09F 9/30 in which the desired character or characters are formed by combining individual elements panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00

Abstract

A light guide with optics guides light exiting the guide. The device achieves accurate control of the reflected light by extracting light from a limited area of the light guide. The configuration of the reflectors used for the selective extraction determines the nature of the output light. The reflectors may be located on a side of the light guide opposite to an output side of the light guide.

Claims

1. A light guide system, comprising:

a light guide comprising a first surface, a second surface, and a third surface, wherein light entering through the first surface propagates along the light guide by total internal reflection between the second surface and the third surface; and

elements that are arranged with respect to the light guide to disrupt the total internal reflection of the propagating light, each element in physical contact with a respective portion of the second surface, each contact element configured such that a portion of the light that is incident thereon is transmitted therethrough; and

a respective reflector positioned to receive the light transmitted through each element, the reflector having a curvature such that the light is reflected back into the light guide and exits the light guide through the third surface;

wherein the elements each comprise a contact portion that physically contacts the second surface and the contact portion is small compared to the reflectors such that the elements function as quasi-point sources.

2. The light guide system of claim 1, wherein the reflectors are configured such that the light is reflected in a predetermined direction and pattern.

3. The light guide system of claim 1, wherein the contact portion of the element is index matched to the light guide.

4. The light guide system of claim 1, additionally comprising a region between the light guide and the elements outside the contact portions thereof, the region lower in refractive index than the light guide.

5. The light guide system of claim 4, wherein the region is configured as a hollow space between the light guide and each reflector.

6. The light guide system of claim 5, wherein the hollow space is substantially coextensive with the reflector.

7. The light guide system of claim 1, wherein:

each of the elements comprises a surface remote from the light guide; and

the respective reflector is located on the surface of the element.

8. The light guide system of claim 1 wherein at least the contact portions of the elements are integral with the light guide.

9. The light guide system of claim 1, additionally comprising a thin layer of a material between the light guide and the reflector, the material lower in refractive index than the light guide.

10. The light guide system of claim 1, wherein the reflector comprises a cylindrical reflective surface.

11. The light guide system of claim 1, wherein the reflector comprises a spherical surface.

12. The light guide system of claim 1, additionally comprising a light emitting diode light source positioned adjacent the first surface of the light guide.